Artemisinin is a sesquiterpene lactone which has been shown to be very effective in the control of certain forms of malaria. The source of the compound is the herb Artemisia annua. The project proposed here is intended to investigate methods for increasing the concentration and yield of artemisinin from cultivated A. annua. Because artemisinin is a secondary metabolite, it is hypothesized that stress will increase its concentration. Plants of A. annua will be subjected to water and nutrient stress under controlled environment conditions. In addition, the carbon:nitrogen ratio of the plants will be increased by growing the plants under elevated atmospheric C02 concentration. Increases in the carbon:nitrogen ratio are expected to increase the concentration of carbon-based compounds such as artemisinin. After environmental effects are investigated, a number of accessions will be screened for differences in yield of artemisinin. A third phase of the project will be the introduction of Artemisia annua to Puerto Rico and the systematic investigation of techniques for its cultivation. The artemisinin produced in the project will be tested against several trematode and cestode parasites, including Schistosoma mansoni and S. japonicum.